Missouri Emerald Ash Borer ProgramUniversity of Missouri Extension.
Emerald ash borer (Agrilus planipennis) is an exotic, invasive, wood-boring insect that infests and kills native North American ash trees, both in forests and landscape plantings. With EAB now in several areas of the Show-Me State - and its ability to hitchhike on firewood - the probability of it spreading to noninfected areas in the state is high.

Slow the Spread of Thousand Cankers DiseaseUniversity of Missouri. Extension.
Although not yet detected here, thousand cankers disease (TCD) is a potentially fatal disease of black walnut, caused by the walnut twig beetle (Pityophthorus juglandis) and an associated fungus (Geosmithia morbida). TCD could easily spread to Missouri from the several eastern and western states where TCD is already present. You can help minimize the chances of spreading TCD by following these steps: